Typically, data quality in a digital repository such as a database for example can be improved using data quality rules to identify records that violate those rules and modifying the data to remove the violations. Both the data being considered and the rules are generally visible to the party that is processing and cleaning the data.
In order to preserve the privacy of the data and the rules that are being used it is typical to use complex cryptographic techniques or to rely on a trusted third party. Cryptographic techniques are typically computationally expensive, and can involve introducing a third party into the system which may not be desirable in many security settings. At the same time, for a large amount of data, the speed at which data is examined for violations and subsequently repaired important.